LGT HAS NMAC WITH MDT DURING DSCNT. TCASII RA SAVES THE DAY.

Narrative

CLRED TO SEA VIA OLYMPIA 1 ARR; TO CROSS OLM AT 12000 FT THEN DSND TO 10000 FT. OUTBOUND FROM THE OLM VOR ON THE 019 DEG RADIAL DSNDING TO 10000 FT; A TCASII TA ALERT INDICATED TFC AT 12 O'CLOCK; 6 MI AT 10000 FT. AFTER ONLY 1 TA ALERT; A TCASII RA ALERT IMMEDIATELY FOLLOWED WITH A 2000 FPM PULL UP COMMANDED. AN EMER PULL UP WAS BEGUN AT 10200 FT. DURING THE PULL-UP A WHITE MDT ACFT PASSED DIRECTLY UNDER OUR NOSE ON A RECIPROCAL HDG AT AN INDICATED 10000 FT. MISS DISTANCE 500 VERT FT OR LESS. TCASII CLR OF TFC SOUNDED AT 11200 FT AND ARR TO SEA WAS CONTINUED. ENTIRE TCASII EVENT LASTED LESS THAN 1 MIN. THE APCH CTLR WAS INFORMED OF THE INCIDENT AND WAS TOLD THAT A 'NEAR MISS' HAD OCCURRED. HE REPLIED THAT HE HAD NOT PREVIOUSLY SEEN THE TFC BUT HE NOW SAW THE TFC. HE STATED THAT HE WAS NOT CTLING THE TFC; NOR WAS THE TFC ON HIS FREQ. HE ALSO MADE A STATEMENT THAT HE HAD BEEN DISTR FROM HIS CTL DUTIES BY AN EQUIP FAILURE OF SOME KIND. IT IS MY OPINION THAT THE TCASII RA COMMAND AND THE EXECUTION OF SOP PROCS SAVED THIS ACFT FROM A MIDAIR COLLISION.